Cardboard containers and the like typically are formed from flat blanks of deformable paperboard materials. Before forming the container, the flat blanks of material are preconditioned with score lines, perforated lines and/or the like, which assist or readily enable the blank of material to be folded into a predetermined three dimensional configuration. Cardboard containers for numerous products including foods, beverages, pharmaceuticals and the like are formed in this manner.
In order to facilitate tearing, removal or separation of the material along predetermined lines, tear lines are established in the blank by perforating the material. The blank can also have score lines formed therein. Generally described, a score line is an indentation in one surface of the material, which typically, but not necessarily, causes a corresponding protuberance from the opposite surface of the material. Score lines are utilized to precondition the blank material for folding and typically are created with a die set, which generally includes a die plate and a counter plate. The die plate generally has a scoring rule or protrusion formed therein, while the counter plate generally has a recess complimenting the scoring rule on the die plate. The deformable material being treated is positioned between the die plate and the counter plate so that when the die plate is advanced against the counter plate under pressure, the material is deformed creating a recess in one surface, corresponding to the scoring rule, and a protrusion in the opposite surface, corresponding to the recess in the counter plate. The material is readily folded in the direction of the recess created therein to allow easy configuration of a container from the deformable blank of material.
In order to more easily fold along score lines, it is conventional to form at least one elongate cut in the protrusion that has previously been formed in the blank material, with the cut being formed in the side of the blank material having the protrusion. Cutting operations such as these are commonly used in gusseted corners of containers, for facilitating easier folding inwardly. These gusseted corners are generally formed at adjacent folded walls of the container.
It is conventional for the score and associated cut to be formed in a multi-step process. First, the score is formed with the die plate and counter plate and, in a subsequent step that occurs after there being relative movement for alignment purposes, a knife is used to the form the cut. The cut typically protrudes approximately fifty percent into the thickness of the blank material.
The conventional method for forming a reverse cut along a score line is time consuming and can be inaccurate; therefore, improvements are desired.